施氮量对豫北冬小麦产量及子粒主要矿质元素含量的影响

以兰考矮早8、豫麦49-198和平安8号为材料,设置5个氮素水平（0、120、180、240、360kg/hm ²）,研究不同施氮量对豫北冬小麦子粒产量及其N、P、K、Ca、Mg、Fe、Mn、Cu、Zn、B等矿质元素含量的影响。结果表明：子粒中N与B（r=0.879）、N与Mg（r=0.858）、Mg与Zn（r=0.871）、Mg与B（r=0.877）含量间相关系数较高。施氮显著提高了子粒N、Ca、Fe、Cu、Zn、B含量,K、Mg含量受施氮量影响较小,但P和Mn含量明显下降。兰考矮早8子粒中各种矿质元素（除B外）含量明显高于平安8号,豫麦49-198介于二者之间。施氮在提高小麦子粒产量的同时降低了P/Ca、P/Mg、P/Fe和P/Zn的值,增强了Ca、Mg、Fe、Zn的生物有效性。此外,研究发现施氮量达到180kg/hm ²后,继续增施氮肥小麦产量难以提升。可见,合理的氮肥管理可以提高豫北地区冬小麦产量及子粒中微量元素的含量;过量施氮不仅难以提高子粒产量,还会降低子粒P和Mn的含量。

Effects of Nitrogen Application Rates on Yield and Mineral Concentrations of Winter Wheat Grains in the North of Henan Province

Lankaoaizao 8 (LKAZ8), Yumai 49-198 (YM49-198) and Ping′an 8 (PA8) were selected as experimental materials. Five N levels (0, 120, 180, 240 and 360kg/hm ²) were conducted. The effects of different N application rates on the contents of mineral elements such as N, P, K, Ca, Mg, Fe, Mn, Cu, Zn and B in winter wheat were studied. The results showed that the concentrations of N, Ca, Fe, Cu, Zn and B in wheat grains increased with increasing of N application rates. K and Mg concentration of grains were less affected by N application, but the contents of P and Mn were significantly decreased with the increasing of N application rates. Highly significant positive correlations between the concentrations of N and B (r=0.879), N and Mg (r=0.858), Mg and Zn (r=0.871), and Mg and B (r=0.877) were also observed. The concentration of various mineral elements (except B) in the grains of LKAZ8 was significantly higher than that of PA8, and YM49-198 was situated between them. Application of N fertilizer increased the grain yield of wheat, reducing the ratio of P/Ca, P/Mg, P/Fe and P/Zn, and enhancing the bioavailability of Ca, Mg, Fe, Zn. In addition, it was found that the yield of wheat could not be increased by increasing N fertilizer after the application rate of nitrogen reached 180kg/hm ². Hence, reasonable N fertilizer management could increase the yield of winter wheat and the content of medium and microelements in northern Henan. Excessive N application was not only difficult to increase grain yield, but also reduced the content of P and Mn in the grains.